A robot is a mechanical device that sometimes resembles a human and is capable of performing a variety of often complex human tasks on command or by being programmed in advance.

Ut-1 Ultra Trencher

The Ut-1 Ultra Trencher is the biggest sea-sub robot in the world. It weighs about 50 tons and goes as fast as 2 to 3 knots. The purpose of the Ut-1 Ultra Trencher, is to lay down pipes at the bottom of the ocean. Those pipes are used for oil and gas.